import SwiftUI

// MARK: - Unified Search Results

/// Shows ChadMusic library results and Soulseek sources in a single view.
/// Pushed onto CloudBrowserView's navStack when user submits a search query.
struct UnifiedSearchResultsView: View {
    let query: String
    @Binding var navStack: [CloudNavDestination]

    @State private var coordinator = UnifiedSearchCoordinator()
    @EnvironmentObject private var theme: AppTheme

    var body: some View {
        VStack(spacing: 0) {
            // Phase indicator
            searchPhaseHeader

            Divider()

            // Results
            Group {
                switch coordinator.phase {
                case .idle:
                    EmptyView()

                case .searchingCloud:
                    searchingView("Searching your library...")

                case .searchingSoulseek:
                    searchingView("Not in library. Searching Soulseek...")

                case .error(let msg):
                    errorView(msg)

                case .done:
                    if coordinator.cloudResults.isEmpty && coordinator.soulseekSources.isEmpty {
                        noResultsView
                    } else {
                        resultsList
                    }
                }
            }

            // Download progress bar
            if coordinator.downloadPhase != .idle {
                downloadStatusBar
            }
        }
        .task {
            coordinator.search(query: query)
        }
    }

    // MARK: - Subviews

    private var searchPhaseHeader: some View {
        HStack(spacing: 8) {
            Image(systemName: "magnifyingglass")
                .foregroundStyle(theme.secondaryText)
            Text("\"\(query)\"")
                .font(.system(size: 13, weight: .medium))
                .foregroundStyle(theme.primaryText)
                .lineLimit(1)
            Spacer()

            if coordinator.phase == .searchingCloud || coordinator.phase == .searchingSoulseek {
                ProgressView()
                    .controlSize(.small)
            }
        }
        .padding(.horizontal, 12)
        .padding(.vertical, 8)
        .background(theme.toolbarBackground.opacity(0.3))
    }

    private func searchingView(_ message: String) -> some View {
        VStack(spacing: 12) {
            Spacer()
            ProgressView()
                .controlSize(.regular)
            Text(message)
                .font(.system(size: 13))
                .foregroundStyle(theme.secondaryText)
            Spacer()
        }
        .frame(maxWidth: .infinity, maxHeight: .infinity)
    }

    private func errorView(_ message: String) -> some View {
        VStack(spacing: 8) {
            Spacer()
            Image(systemName: "exclamationmark.triangle")
                .font(.title)
                .foregroundStyle(theme.secondaryText)
            Text(message)
                .font(.system(size: 12))
                .foregroundStyle(theme.secondaryText)
                .multilineTextAlignment(.center)
                .padding(.horizontal, 20)
            Button("Retry") {
                coordinator.search(query: query)
            }
            .controlSize(.small)
            Spacer()
        }
        .frame(maxWidth: .infinity, maxHeight: .infinity)
    }

    private var noResultsView: some View {
        VStack(spacing: 8) {
            Spacer()
            Image(systemName: "magnifyingglass")
                .font(.system(size: 32))
                .foregroundStyle(theme.tertiaryText)
            Text("No results for \"\(query)\"")
                .font(.system(size: 13))
                .foregroundStyle(theme.secondaryText)
            if !SlskdAPIClient.shared.isConfigured {
                Text("Configure Soulseek in Settings to search beyond your library.")
                    .font(.system(size: 11))
                    .foregroundStyle(theme.tertiaryText)
                    .multilineTextAlignment(.center)
                    .padding(.horizontal, 20)
            }
            Spacer()
        }
        .frame(maxWidth: .infinity, maxHeight: .infinity)
    }

    private var resultsList: some View {
        List {
            // ChadMusic results
            if !coordinator.cloudResults.isEmpty {
                Section {
                    ForEach(coordinator.cloudResults) { album in
                        Button {
                            navStack.append(.album(album))
                        } label: {
                            HStack {
                                VStack(alignment: .leading, spacing: 2) {
                                    Text(album.title)
                                        .font(.system(size: 13))
                                        .foregroundStyle(theme.primaryText)
                                        .lineLimit(1)
                                    if let artist = album.artist {
                                        Text(artist)
                                            .font(.system(size: 11))
                                            .foregroundStyle(theme.secondaryText)
                                            .lineLimit(1)
                                    }
                                }
                                Spacer()
                                if let count = album.trackCount {
                                    Text("\(count) tracks")
                                        .font(.system(size: 11))
                                        .foregroundStyle(theme.tertiaryText)
                                }
                                Image(systemName: "chevron.right")
                                    .font(.caption2)
                                    .foregroundStyle(theme.tertiaryText)
                            }
                        }
                        .buttonStyle(.plain)
                    }
                } header: {
                    Label("In Your Library", systemImage: "cloud.fill")
                        .font(.system(size: 11, weight: .semibold))
                        .foregroundStyle(theme.accent)
                }
            }

            // Soulseek results
            if !coordinator.soulseekSources.isEmpty {
                Section {
                    ForEach(coordinator.soulseekSources) { source in
                        SoulseekSourceRow(
                            source: source,
                            isDownloading: coordinator.downloadPhase.isActive,
                            onDownload: {
                                coordinator.downloadSource(
                                    source.response,
                                    artist: guessArtist(from: query),
                                    albumName: query
                                )
                            }
                        )
                        .draggable(source.dragRepresentation)
                    }
                } header: {
                    Label("Available on Soulseek", systemImage: "arrow.down.circle.fill")
                        .font(.system(size: 11, weight: .semibold))
                        .foregroundStyle(Color(red: 1.0, green: 0.55, blue: 0.0))
                }
            }
        }
        .listStyle(.inset)
    }

    private var downloadStatusBar: some View {
        HStack(spacing: 10) {
            switch coordinator.downloadPhase {
            case .downloading(let progress):
                ProgressView(value: progress)
                    .progressViewStyle(.linear)
                    .frame(width: 80)
                Text("Downloading... \(Int(progress * 100))%")
                    .font(.system(size: 11))
                    .foregroundStyle(theme.secondaryText)
            case .importing:
                ProgressView()
                    .controlSize(.small)
                Text("Importing to ChadMusic...")
                    .font(.system(size: 11))
                    .foregroundStyle(theme.secondaryText)
            case .complete(let name):
                Image(systemName: "checkmark.circle.fill")
                    .foregroundStyle(.green)
                Text("\(name) ready")
                    .font(.system(size: 11))
                    .foregroundStyle(theme.secondaryText)
            case .failed(let msg):
                Image(systemName: "exclamationmark.triangle.fill")
                    .foregroundStyle(.red)
                Text(msg)
                    .font(.system(size: 11))
                    .foregroundStyle(.red)
                    .lineLimit(1)
            case .idle:
                EmptyView()
            }

            Spacer()

            if coordinator.downloadPhase.isActive {
                Button("Cancel") {
                    coordinator.cancel()
                }
                .controlSize(.small)
            } else if coordinator.downloadPhase != .idle {
                Button("Dismiss") {
                    coordinator.dismissDownload()
                }
                .controlSize(.small)
            }
        }
        .padding(.horizontal, 12)
        .padding(.vertical, 8)
        .background(.ultraThinMaterial)
    }

    // MARK: - Helpers

    /// Try to extract artist from query (e.g., "Pink Floyd - Wish You Were Here" → "Pink Floyd").
    /// Falls back to the full query.
    private func guessArtist(from query: String) -> String {
        // If we have cloud results from the same search, use the first artist
        if let artist = coordinator.cloudResults.first?.artist {
            return artist
        }
        // Try "Artist - Album" format
        if let dashRange = query.range(of: " - ") {
            let artist = String(query[query.startIndex..<dashRange.lowerBound])
                .trimmingCharacters(in: .whitespaces)
            if !artist.isEmpty { return artist }
        }
        return query
    }
}

// MARK: - Score Badge

/// Color-coded quality score indicator for Soulseek search results.
struct ScoreBadge: View {
    let score: Int

    private var color: Color {
        if score >= 120 { return Color(red: 0.2, green: 0.9, blue: 0.4) }
        if score >= 80 { return Color(red: 1.0, green: 0.8, blue: 0.0) }
        return Color(red: 0.8, green: 0.3, blue: 0.3)
    }

    var body: some View {
        Text("\(score)")
            .font(.system(size: 11, weight: .bold, design: .monospaced))
            .foregroundStyle(color)
            .padding(.horizontal, 6)
            .padding(.vertical, 2)
            .background(
                RoundedRectangle(cornerRadius: 4)
                    .fill(color.opacity(0.15))
                    .overlay(
                        RoundedRectangle(cornerRadius: 4)
                            .stroke(color.opacity(0.3), lineWidth: 0.5)
                    )
            )
    }
}

// MARK: - Soulseek Source Row

/// A single Soulseek search result showing quality score, format, file count, and download button.
struct SoulseekSourceRow: View {
    let source: ScoredSoulseekSource
    var isDownloading: Bool = false
    let onDownload: () -> Void

    @EnvironmentObject private var theme: AppTheme
    @State private var isExpanded = false

    var body: some View {
        VStack(alignment: .leading, spacing: 0) {
            HStack(spacing: 10) {
                // Quality score badge
                ScoreBadge(score: source.score)

                // Source info
                VStack(alignment: .leading, spacing: 2) {
                    HStack(spacing: 6) {
                        Text(source.formatDisplay)
                            .font(.system(size: 11, weight: .bold, design: .monospaced))
                            .foregroundStyle(formatColor)
                        Text("\(source.audioFileCount) files")
                            .font(.system(size: 11))
                            .foregroundStyle(theme.secondaryText)
                        Text(source.formattedTotalSize)
                            .font(.system(size: 11))
                            .foregroundStyle(theme.secondaryText)
                        if source.response.hasFreeUploadSlot {
                            Image(systemName: "bolt.fill")
                                .font(.system(size: 9))
                                .foregroundStyle(Color(red: 0.2, green: 0.9, blue: 0.4))
                        }
                    }

                    HStack(spacing: 6) {
                        Text(source.response.username)
                            .font(.system(size: 10))
                            .foregroundStyle(theme.tertiaryText)
                            .lineLimit(1)
                        if source.response.queueLength > 0 {
                            Text("Queue: \(source.response.queueLength)")
                                .font(.system(size: 10))
                                .foregroundStyle(theme.tertiaryText)
                        }
                    }
                }

                Spacer()

                // Expand file list
                Button {
                    withAnimation(.easeInOut(duration: 0.2)) { isExpanded.toggle() }
                } label: {
                    Image(systemName: isExpanded ? "chevron.up" : "chevron.down")
                        .font(.system(size: 10))
                        .foregroundStyle(theme.tertiaryText)
                }
                .buttonStyle(.plain)

                // Download button
                Button {
                    onDownload()
                } label: {
                    Image(systemName: "arrow.down.circle.fill")
                        .font(.system(size: 18))
                        .foregroundStyle(source.score >= 80 ? theme.accent : theme.tertiaryText)
                }
                .buttonStyle(.plain)
                .disabled(isDownloading || source.score < 30)
                .help(source.score >= 80
                      ? "Download this source"
                      : "Quality too low (score: \(source.score))")
            }
            .padding(.vertical, 3)

            // Expandable file list
            if isExpanded {
                VStack(alignment: .leading, spacing: 1) {
                    ForEach(source.audioFiles, id: \.filename) { file in
                        HStack(spacing: 8) {
                            let name = file.filename
                                .replacingOccurrences(of: "\\", with: "/")
                                .split(separator: "/").last.map(String.init) ?? file.filename
                            Text(name)
                                .font(.system(size: 10, design: .monospaced))
                                .foregroundStyle(theme.secondaryText)
                                .lineLimit(1)
                            Spacer()
                            Text(ByteCountFormatter.string(fromByteCount: file.size, countStyle: .file))
                                .font(.system(size: 10, design: .monospaced))
                                .foregroundStyle(theme.tertiaryText)
                            if let br = file.bitRate, br > 0 {
                                Text("\(br)k")
                                    .font(.system(size: 10, design: .monospaced))
                                    .foregroundStyle(theme.tertiaryText)
                            }
                        }
                    }
                }
                .padding(.leading, 40)
                .padding(.vertical, 4)
            }
        }
        .opacity(source.score >= 80 ? 1.0 : 0.5)
    }

    private var formatColor: Color {
        switch source.bestFormat {
        case "FLAC", "WAV", "AIFF", "AIF": Color(red: 0.2, green: 0.9, blue: 0.4)
        case "APE", "WV", "M4A": Color(red: 0.3, green: 0.8, blue: 0.95)
        case "MP3": Color(red: 1.0, green: 0.8, blue: 0.0)
        default: theme.tertiaryText
        }
    }
}